Wireless devices and systems, such as those used for information communication, rely on battery power. When depleted, batteries are replaced or recharged. Battery replacement is costly and battery recharging typically entails a physical electrical connection with metered line service. A connection with a metered line service requires that the device remain tethered by a cord and this can be inconvenient.
Current technology for wireless power, while it removes the restrictions imposed by a corded connection, is often times severely limited due to the close proximity and accurate alignment that are required between transmitter and receiver. These limitations can significantly impair the widespread adoption of wireless power technology.
In magnetic resonant coupling based wireless charging systems, energy transfer efficiency heavily depends on how the driving frequency, the transmitter resonant frequency and the receiver resonant frequency match each other, especially since the transmitter and receiver typically use high Q factor coils.
Fixing driving frequency based on a static system design and the system's intrinsic resonant frequency often severely degrades end to end energy transfer efficiencies. Therefore, maximum distances and misalignment tolerances of coils in conventional wireless energy systems can limit the system's applicability in many applications. In addition, it can become overly expensive to produce in high volumes wireless energy transfer systems that maintain precise static natural frequencies in the high-Q resonators that are typically fabricated for conventional wireless energy transfer systems.